Richard Holloway, the executive producer behind such TV shows as the U.K. version of The X Factor and Britain's Got Talent, ‎on Tuesday (Sept. 22) suggested the big entertainment formats may be aging, but could continue their on-air run for at least a while longer.

"Nothing is forever," the TV veteran, who leads FremantleMedia U.K.'s production firm Thames, told a Royal Television Society event in London when asked how much longer ITV singing competition X Factor could air, adding that there was no entertainment program without a life span.

He acknowledged that the X Factor's overnight ratings have declined again this year, but emphasized that "viewing habits have changed enormously, especially in the last couple of years ... we all got to appreciate that and kind of consider it more." He said media coverage was still often obsessed with overnight data, even though that does not fully show the "true story" as on-demand viewing was bigger nowadays.

About ITV's BGT, the most-watched show in Britain this year, Holloway said it was a "more engaged format" than other hit shows in the U.K., such as the BBC's The Great British Bake Off. "I think it could run for many, many years. It's our most profitable show," Holloway said. X Factor"will have a finite life span. But I think you then rest it, then you bring it back."

‎Concluded the producer: "As long as we produce the show to a standard, which the public really, really wants to see ... then there is no reason why we can't produce it for years and years and years."

Asked about X Factor creator and judge Simon Cowell, Holloway said: "It's been a really good relationship" and "fantastic collaboration" with him.‎ "It's a give-and-take relationship," even though he said he doesn't always agree where the two end up in debates.

‎Describing the differences between the two big entertainment shows, Holloway said X Factor was "quite intense" and "pretty full on," while BGT was more fun.

‎Could Netflix or Amazon end up ordering original entertainment shows in addition to dramas and comedies? Holloway said that may happen down the line, but emphasized that drama provided "great IP" that digital companies can use or sell globally. In comparison, entertainment shows are "quite parochial" and don't always travel as well, he said, highlighting that the British X Factor and BGT have been sold abroad, but mostly to smaller networks.